v2.4.0.6
Document And Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Jun. 30, 2011
Feb. 03, 2012
Class A [Member]
Feb. 03, 2012
Class B Convertible [Member]
Document Type 10-K      
Amendment Flag false      
Document Period End Date Dec. 31, 2011      
Document Fiscal Period Focus FY      
Document Fiscal Year Focus 2011      
Trading Symbol mstr      
Entity Registrant Name MICROSTRATEGY INC      
Entity Central Index Key 0001050446      
Current Fiscal Year End Date --12-31      
Entity Filer Category Large Accelerated Filer      
Entity Current Reporting Status Yes      
Entity Voluntary Filers No      
Entity Well-known Seasoned Issuer Yes      
Entity Public Float   $ 1,334.3    
Entity Common Stock, Shares Outstanding     8,404,942 2,377,830